Method of preparing monoquaternary nitrogen compounds



United States Patent 3,150,138 IiiETHGD 0F PREPARHIJG MQNGQUATERNARYNETRGGEN COMPOUNDS Frank Miller, Wilmington, Del, assignor to AirProducts and Chemicals, Zine, a corporation of Delaware No Drawing.Filed Feb. 14, 1961, Sex. No. 89,111 5 Claims. (Cl. 260-468) Thisinvention relates to cage structure heterocyclic nitrogen compoundshaving both a quaternary nitrogen and a tertiary nitrogen and to methodsof preparing the same. These monoquaternary nitrogen compounds can bedesignated as l-allcyl-4-aza-l-azoniabicyclo-(2.2.2)- octane halides andl-alkyl-4-aza-1-azoniabicyclo-(2.2.2)- octane hydroxides. Such compoundshave the generic structure in which R is hydrogen or a hydrocarbonradical of up to carbon atoms; and X is either halogen of the groupconsisting of chlorine, bromine and iodine, or hydroxyl. Thequaternizing group of the quaternary nitrogen is always a primary groupand is attached to the quaternary nitrogen through a CH linkage;accordingly, the substituents are considered alkyls and include theradicals derived from aliphatic hydrocarbons and substituted aliphaticssuch as the benzyl radical, C H CH In prior art literature, such as anarticle by S. Oae et al., J. Org. Chem. 24, 1348 (1959), both mono anddiquaternary derivatives of 1,4-diazabicyclo-octane are described. Oaeet al. show the formation of diquaternary compounds from primary alkylhalides. The only monoquaternary compounds obtained were formed fromsecondary alltyl halides because of a simultaneous substitution anddehydrohalogenation reaction. N 0 primary compounds were formed. Oae eta1. employed solvents such as methanol, carbon tetrachloride and acetonewith variations in the reflux time controlled in part by the ease ofreactivity of the halide employed.

In accordance with the present invention, an alkylor aralkyl halide(chloride, bromide or iodide) having 1 to 11 carbon atoms, is added to asolution of 1,4-diazabicyclo-(2.2.2)-octane in a hydrocarbon solvent,and the reaction mixture is heated at a temperature of at least 80 C.for at least one hour, thereby forming and precipitating solid 1 alkyl4-aza-l-azoniabicyclo-(2.2.2)- octane halide, which is separated fromthe cooled reaction mixture. Conversion of the halide to the hydroxideis readily effected by base exchange.

The nature of the invention is further clarified by reference to aplurality of examples.

Example I A resin kettle having a Water-cooled reflux condensercontained a solution of 224 g. (2 mole) of triethylenediamine in oneliter of benzene, which solution contained about 20% by weight or about15 mol percent triethylenediamine. Into the refluxing and stirredsolution, 210 g. (2.27 mols or 13.5% excess) of l-chlorobutane was addeddropwise during an hour. The refluxing and stirring were continued foran additional 16 hours. The 1- chlorobutane reacted withtriethylenediamine to form a monoquaternary salt. Of particularimportance, l-n-butyl- 4-aza-l-azoniabicyclo-(2.2.2)-octane chloride wasso in soluble in the refluxing benzene that as it formed, itprecipitated. Even after the addition of the excess butyl chloride, noneof the precipitated monoquaternary salt reacted therewith, inasmuch asthe reaction conditions were too mild to initiate reaction between thesolid precipitate and the dissolved butyl chloride.

3,150,138 Patented Sept. 22, 1964 The solution was cooled to roomtemperature and filtered through aBiichner funnel. The precipitate wasrinsed with one liter of benzene, partially dried under a heat lamp for90 minutes and then further dried in a vacuum oven overnight at about 65C. The 371 g. of butyl monoquaternary salt recovered was 91% of thestoichiometric yield. The compound,l-n-butyl-4-aza-lazoniabicyclo-(2.2.2)-octane chloride, was afree-flowing white powder, soluble in water, and had a melting pointover the range of lOl-l03.5 C.

Example II A 4 liter resin kettle contained 1 liter of benzene and 224g. (2 mole) of triethylenediamine. This solution was stirred andmaintained at the initial reflux temperature during the dropwiseaddition of 1136 g. (8 mols plus 123.4 g. or a severalfold excess)benzenyl chloride during 2 hours. The temperature was maintained atabout 85 C. for an additional 4 hours. The reaction mixture was cooled,and the precipitated product was filtered on a Biichner funnel, rinsedwith 1 liter of benzene, triturated with acetone, and vacuum dried at 60C. The l-benzyl- 4-aza-1-azoniabicyclo-(2.2.2)-octane chloride wasanalyzed for chloride content and found to have 14.86% chlorinei0.04%thus confirming the monoquaternary ructure, 14.85% being the theoreticalchloride content of the desired compound, and distinguishing it from thedibenzyl diquaternary compound which contains 19.4% chloride. Thus aconsiderable excess of highly reactive benzyl chloride does not preventthe isolation of the monoquarternary salt in high purity. Otherpreparations of lbenzyl-4-azal-azoniabicyclo- (2.2.2) -octane chloridemay involve the use of a smaller quantity of benzyl chloride;

however, the presence of a relatively large excess of the haloalkane hasadvantages of increasing yields and reducing reaction time; theunreacted portion is readily recovered for reuse.

In demonstrating the usefulness of the monoquaternarytriethylenediarnine salts of the present invention, samples of sheetsteel are electrolytically nickel plated in an aqueous nickel chloridebefore and after the addition of the monoquaternary salt to theelectroplating bath. The combination of the tertiary amine group and thequaternary group modifies the electroplating action so that the nickelplate is brighter, more adherent and more satisfactory than in theabsence of the monoquaternary triethylenediamine salt. The nickel toquaternary mol ratio is desirably about 2 to 1.

Example [H Halide salts of l-benzyl-4-aza-l-azoniabicyclo(2.2.2)- octaneare prepared following the general procedure of Example 11 but usingbenzyl bromide and benzyl iodide instead of benzyl chloride.

In each case, a satisfactorily pure monoquaternary benzyltriethylenediamine salt is obtained. By treatment of an aqueous solutionof the monoquaternary salt with an excess of the hydroxide form of ionexchange resin, such salt solution may be converted to the correspondingquaternary hydroxide solution.

Example I V Monoquaternary triethylenediamine chloride salts areprepared following the general procedure of Example I but using insteadof l-chlorobutane other reactive primary monochlorohydrocarbons havingfrom 1 to 11 carbon atoms. High purity compounds, free from thediquaternary chloride salts, are obtained by using such compounds aschloromethane, l-chloropropane, l-chloropentane,l-chloro-2,2,3,3-tetramethylbutane, or l-chloromethylnaphthalene. it isto be noted that reactions involving compounds which may be fugitive atabout or below the reaction temperature (of about C. or

higher) are eilected in a suitably closed system; such low boilingcompounds include chloromethane, chloroethane and l-chloropropane. Themethod is operable when the organic halide is selected from compoundsdesignated by the formula C H X in which n is a number from 1 to 11 andy is a number not greater than 212 plus 1, and in X is an elementselected from the group consisting of chlorine, bromine, and iodine. Thehalide salt of l-alkyl- 4-aza-l-azoniabicyclo-(2.2.2)-octane isconverted to the hydroxide compound by any conventional procedure; onesuch treatment of preferred form includes treating an aqueous solutionof the halide salt with granules of the basic form of ion exchangeresin. Such uses include catalysis, apparently through the quaternaryfunction, of the polymerization of isocyanates and propylene oxide;also, polyurethane formation is promoted, apparently through thetertiary amine function of these compounds.

The quaternary hydroxide compound has a variety of special uses. Certainquaternary salts can be made by exchange of one halide for anotherhalide by treatment of one quaternary salt with a suitable ion exchangeresin. Likewise, the hydroxide form may be used in the preparation ofwhatever salt is desired by neutralization with the corresponding acid,which might be a hydrohalic acid such as hydrochloric, hydro'oromic, orhydriodic acid.

Obviously many modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and therefore only such limitations should be imposed asare indicated in the appended claims.

What is claimed is:

1. The method of preparing a monoquaternary triethylenediamine halidesalt having the formula:

l[ N NoH2.R X-

in which X designates an anion selected from the group consisting ofchlorine, bromine and iodine, and in which R is selected from the groupconsisting of H, phenyl, and alkyl having up to 10 carbon atoms; whichmethod consists of the steps of: preparing a hot solution oftriethylenediarnine in benzene; adding to such hot solution ahydrocarbon halide RCH X in which R and X are as previously defined;agitating the reaction mixture of triethylenediamine, hydrocarbon halideand the benzene solvent at a temperature of at least 80 C. for more thanone hour to precipitate the monoquaternary triethylene' diamine salt;cooling the reaction mixture; separating the liquid from the salt,

2. The method of claim 1 in which the molar quantity of RCH X is greaterthan the molar quantity of triethylenediamine and in which all of theexcess RCH X is removed Wlth the solvent and in which no contaminantdiquaternary triethylenediamine salt forms because of the insolubilityof the monoquaternary triethylenediamine in the benzene solvent.

3. The method of claim 1 in which RCH X is normal butyl chloride.

4. The method of claim 1 in which RCH X is benzyl chloride.

5. The method of preparing monoquaternary compounds having the formula.

in which R is selected from the group consisting of hydrogen, phenyl,and alkyl of up to 10 carbon atoms; which method includes the steps of:preparing a hot solution of 1,4-diazabicyclo-(2.2.2)-octane in a benzenesolvent; adding to such hot solution an organic halide compoundcontaining the RCH2 radical attached to halogen in which the R isdefined as in the formula and halogen is selected from the groupconsisting of chlorine, bromine, and iodine; agitating the reactionmixture of 1,4-diazabicyclo-(2.2.2.)-octane, organic halide and thebenzene solvent at a temperature of at least 80 C. for more than onehour to precipitate a monoquaternary halide; cooling the reactionmixture; separating the precipitated monoquaternary halide; removingoccluded liquid from the salt; preparing an aqueous solution of thesalt; and treating the aqueous solution with an excess of granules ofbasic ion exchange resin having exchangeable hydroxide ions.

References Cited in the file of this patent UNITED STATES PATENTS2,834,779 Biel et al. May 13, 1958 2,973,361 Rudner Feb. 28, 19613,010,963 Erner Nov. 28, 1961 OTHER REFERENCES Oae et al.: QuaternaryAmmonium Salts of 1,4-Diazabicyclo-[2.2.2]-octane, Journal OrganicChemistry, vol. 24, pp. 1348-9 (1959).

Farkas et al.: Triethylenediamine, Industrial and Engineering Chemistry,vol. 51, page 1299 (1959).

1. THE METHOD OF PREPARING A MONOQUATERNARY TRIETHYLENEDIAMINE HALIDESALT HAVING THE FORMULA: